The present invention relates to an improved method for treating wood. More particularly, the present invention relates to a method for packaging, dispensing and introducing a chemical agent into the internal structure of wood.
Wood products such as utility poles for electric and telephone transmission wires, piling supports for highway and railroad bridges, marine piles supporting a dock or wharf over water, and solid or laminated wood building structural components are all subject to attack by wood destroying fungi (wood rot) and insects (termites). Frequently, such attack is unnoticed externally but can be extensive internally. One method of combatting such destruction is by the internal application of a chemical agent which is toxic to the wood destroying organisms. Unfortunately, the chemical agent chosen is usually not only toxic to destructive organisms, but is also toxic to man, animals, and the environment as well. The utilization of such chemical treatment agents also presents a severe hazard to those personnel who must handle the toxic chemicals. In addition, where wood pilings are to be the subject of treatment, there is the additional danger of environmental contamination occurring when the treatment agent seeps or spills into the waterway within which the piling is located. Moreover, the conspicuous unattended, application of a chemical fluid to a wood structure over an extended period of time may be interrupted by tampering on the part of children or animals, resulting in their exposure to potentially toxic chemicals.
Presently, there are several known devices used to implement the introduction of a chemical treatment agent into the internal environment of a wood object. These devices enclose the desired toxic chemicals, and when properly inserted into a pre-formed cavity, the chemicals are released by mechanical means. One such example is illustrated by U.S. Pat. No. 3,367,065 wherein the container of toxic material is placed within a prepared cavity located within the interior of a tree. The container is sealed within the tree utilizing a retaining plug having a puncturing means on its inner end. When the retaining plug is impacted into its final position, the end of the container is punctured releasing the contents into the tree interior.
U.S. Pat. No. 3,691,683 discloses a method wherein a cartridge which is at least partially filled with the chemical treating agent is knocked into the tree trunk, by some mechanical means. This method involves shattering the cartridge end under sufficient impact to generate an overpressure in the cartridge for injecting the chemical treating agent into the tree. Such a shattering technique, however, involves an additional element of risk in the event shattered pieces of the cartridge come in contact with personnel impacting the device. Therefore, a demand still remains in the industry today for a method of treating a wood structure with a toxic chemical wherein the risk factors are significantly reduced.